Micropower CMOS GM-C filters for speech signal processing

Author

Hung, Chung-Chih ; Halonen, Kari ; Ismail, Mohammed ; Porra, Veikko

Author_Institution

Dept. of Electr. Eng., Helsinki Univ. of Technol., Espoo, Finland

Volume

3

fYear

1997

fDate

9-12 Jun 1997

Firstpage

1972

Abstract

In this paper, CMOS implementations of two low-voltage, micropower 5th-order elliptic low-pass GM-C filters are presented. Both of the 5th-order elliptic low-pass GM-C filters operate at a supply voltage of 3 V. Their tunable cutoff frequencies are from 3 Hz to 600 Hz and from 140 Hz to 3.5 kHz, respectively. The Operational Transconductance Amplifier (OTA) in these GM-C filter design is implemented by a low-voltage voltage-to-current converter (V-I converter) working in the weak-inversion region. The transconductance can be tuned by DC currents or DC voltage. This V-I converter can also be used as a basic building block to construct low-voltage, micropower analog VLSI signal processing systems. These filters provide a practical means for implementing very large time constants on-chip allowing single-chip solutions at very low frequencies. They can be applied in speech processing systems and other very low frequency applications

Keywords

CMOS analogue integrated circuits; active filters; circuit tuning; elliptic filters; low-pass filters; operational amplifiers; speech processing; 3 Hz to 3.5 kHz; 3 V; 5th-order GM-C filters; CMOS implementations; elliptic low-pass GM-C filters; low-voltage operation; micropower CMOS GM-C filters; operational transconductance amplifier; speech signal processing; tunable cutoff frequencies; CMOS process; Circuits; Cutoff frequency; Laboratories; Low pass filters; Signal processing; Speech processing; Transconductance; Very large scale integration; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 1997. ISCAS '97., Proceedings of 1997 IEEE International Symposium on

Print_ISBN

0-7803-3583-X

Type

conf

DOI

10.1109/ISCAS.1997.621539

Filename

621539